Many vehicles include an Audio Video Navigation (AVN) terminal. Generally, the AVN terminal displays a control screen for controlling various devices installed in the vehicle or a screen for executing additional functions that can be executed on the AVN terminal, in addition to providing information about a route to a destination. A user can manipulate the AVN terminal through a display with a touch screen or a jog shuttle type controller, or using a voice command to control various devices in the vehicle. In the case in which the user manipulates the AVN terminal using a voice command, the vehicle should be able to recognize voice commands during traveling. Accordingly, research for improving a recognition rate of voice commands when a vehicle travels has been conducted.